铽与两种不同结构羧酸配合物的低温固相合成及发光性质研究

以两种不同结构的羧酸苯乙酸和苯基羟基乙酸与氯化铽为原料,采用低温固相反应合成了两种羧酸铽配合物.经元素分析、稀土络合滴定、摩尔电导确定了配合物的组成为:Tb(L1)3·H2O,Tb(L2)3·4H2O(L1=C6H5 CH COO-,L2=C6H5CH(OH)COO-).测定了配体及配合物的IR谱、1H NMR及配体的磷光光谱和铽配合物荧光激发和发射光谱.根据磷光发射光谱数据计算了配体的三重态能级值.比较两个配合物的荧光发射主峰5D4→7F5强度:苯基羟基乙酸铽为苯乙酸铽的5倍.由此可见在配体亚甲基上引入拉电子基团羟基,将会扩大共轭体系π电子的离域范围,提高能量传递效率,提高稀土离子的发光强度.

Synthesis of Two Different Structural Aromatic Carboxylic Acid Complexes with Terbium by Solid State Reaction at Low Temperature and Studies on Luminescence Property

Two solid complexes of terbium with phenylacetic acid (L1) and phenyl-hydroxylacetic acid (L2) were synthesized by solid state reaction at low temperature, and the complexes were characterized by chemical analysis. Elemental analysis and rare earth coordination titration studies suggested that the composition of the complexes is Tb(L1)3) x H2O and Tb(L2)3 x 4H2O respectively. IR spectra and 1H NMR studies indicated that the coordination fashion of the two ligands with Tb(III) is different The ligand (L1) is bonded with Tb(III) ions by two oxygen atoms in carboxyl group which coordinate as a symmetrical chelate bidentate group. The ligand (L2) is bonded with Tb(III) ions by one oxygen atom in carboxyl group. The molar conductivity in DMSO solvent indicates that all complexes are non-electrolyte. The fluorescence spectra of complexes and phosphorescence spectra of the ligands showed that all of the two ligands were sensitized differently by Tb3+ ions for fluorescence intensity, which indicates that the triplet state energy of ligands and the different structure of complexes play an important role in the luminescence of complexes. Fluorescence intensity of Tb(L1)3 x H2O is smaller than that of Tb(L2)3 x 4H2O. So the structure of ligand carboxylic acid has an effect on Tb3+ luminescence in these complexes.